New cells grow from the deepest layer of the epidermis, which is the: adipose tissue, the stratum basale, the stratum corneum, or the dermis?
1 Answer
The stratum basale
Explanation:
The epidermis consists of four strata (layers) - consists of 4 layers: Corneum, Granulosum, Spinosum and Basale (thick skin - e.g. on the soles of your feet - has a fifth layer beneath corneum called Lucidium because it is subject to more wear and tear).
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Here is a summary of what each layer does.
Corneum - This is the outermost, roughest layer that consists of 20 - 30 layers of dead keratinocytes. They are dead, flat cells that are filled with a protein called keratin. They flake off the surface of the skin only to be replaced by new cells that rise up from lower layers.
Lucidum - This layer is only present in thick epidermis Lucidum is latin for clear, which makes sense as the Lucidium consists of 2 - 3 layers of clear, flat, dead keratinocytes
Granulosum The first layer to contain living cells, this layer has a grainy appearance due to the cells being moved up as they produce keratin.
Spinosum The cells in this layer look spiny when dried for a microscope sample because of tiny filaments that join the cells together.
Basal/e The bottom layer, this is where mitosis and most of the cell production occurs. It also connects the epidermis to the dermis.
A useful, but ironic, way to remember these layers is with the following mnemonic:
Come, Lets Get Sun Burnt
Come - Corneum
Lets - Lucidum
Get - Granulosum
Sun - Spinosum
Burned - Basal/e
Hope this helps; let me know if I can do anything else:)